Chain saw



Sept 8, 1953 H. E. WARREN 2,651,336

CHAIN sAw Filed July 11, 1947 3 Sheets-Sheet 2 BOO INVENTOR .x yHf/v/QYc". WAR/PEN,

Sept 8, 1953 H. E. WARREN 2,651,336

CHAIN sAw Filed July 11, 1947 s sheets-sheet' s MSA/RY VVA RR w@MNM/mwah ATTORNEYS s Patented Sept. 8, 1953 Henry E. Warren,

Ashland, Mass., assignor to Lombard Governor Corporation,

Ashland,

Mass., a corporation of Massachusetts Application July 11, 1947, SerialNo. 760,237 3 Claims. (Cl. 143-135) 'Ihe present invention relates topower operated sawing machines of the chain type and to chain sawstherefor. It aims to increase the cutting e'iciency of chain sawsthrough an improved correlation of successive cutting elements, and toreduce manufacturing and maintenance costs as a result-of `new andimproved constructions and arrangements of the link components. l In thedrawings illustrating by way of example certain embodiments of theinvention:

Fig. 1 shows a length of a chain saw in active position sawing crosswiseof a tree, log or timber of which a portion is seen in cross-section;v

Figs. 2 and 3 are respectively front end and side elevations of onecutter link of the chain;

Figs. 4 and 5 arecorresponding views of another cutter link; Y

Fig. 6 is a sectiona1 view on a larger scale taken transversely of thesaw and kerf, substantially Yas though looking from the left at Fig. 1;

y Fig. 7 is av view similar to Fig. 1 illustrating another constructionfor the saw chain o fthe invention;

Fig. 8 is a bottom plan view of the chain length Vof Fig, 7 l

Fig. 9 is a cross-sectional view of the chain as viewed from the leftlooking onto Fig.- '7; j

Figs. 10 andll are front andside elevations of Vone of the cutter linksof the Fig. v'7 chain embodiment;

. Fig. 12 shows a connector link carrying a depthgauging guard and rakerelement; Figs. `13 and 14l are respectively a plan and a "side elevationshowing a grinder means incorporated with the chain sawand comprised inthe presentinvention, said views further illustrating the correlation ofthe cutter chain elements and the grinding instrument; and

Fig. 15 shows on a larger scale the chain links acted upon by thegrinder in Figs. 13 and 14 but horizontally extended as in operativecutting position.

In the chain saw art as heretofore practiced it has been customary toemploy various different shapes and types of teeth and cutting elementsacting in generalto remove wood particles at the edges of the kerf so asto dene the 'latter and then to rout or rake out interior sections ofthe kerf. IIhe action of these cutting teeth has commonly been to ktearaway particles of wood in a somewhat irregular manner requir- `ing adisproportionate power consumption Vas compared for example with theaction of an ellicient cross-cut saw. The present invention isVgenerally characterized by the provision of a separately imade orVdesired: any convenient Vformk .of Vrakei' Vsingle functional type ofcutting tooth acting in the `manner of a plane, chisel or plow andwhere- 1n` the extent of cut by successive cutting memrocal guardingaction.

Referring lirst tothe embodiment of Figs. 1 to 6, in Fig. 1 a portion ofthe longitudinal guide plate of the sawing machine is indicated at I5,

are disposed in longitudinal alinement and are pivotally joined into acontinuous chain by lateral pairs of connector links 50. Each pair ofone at each side of the cenrespective end portions pivotally connectedto the central links yas by riveting at 5 I, 52.

The central links prises a Ibody, a lower rear leg 22, 32, or 42 and inthe illustratedrexample an upper body portion or lug 23,` 33, or-43 forguided travel along the guide plate I5. 'Ifhese blanks for the centrallink seriesare made of a strong and tough material such as springtempered steel but which may be a relatively inexpensive stock ascomparedwith that for the cutting elements or teeth proper in accordancewith the present invention. These latter preferably are Yconstituted astool bits formed of a v as high speed tool steel, tungsten carbidesteel, Stelliteand others. These bits, one of which is seen in Figs. 2and 3 and .another in Figs. 4 and 5, Vare-mounted 'inslots or recessesappropriately located on the-link blanks and lare held in-positionasvbysilver solder, copper welding VOrother suitableattachment A v, In'accordance with the invention the teeth or cut ngj elements of theactive links, whether provided at the spaces'to assist in clearing theheat resistant material such kerf. As slhown the rear legs 43 of theintermediate central links 40 are themselves constituted Aas such rakeror clearer means 44.

In the embodiment of Figs. l to 6 the successive cutting teeth operateat different vertical levels. The central links 20, see particularlyFigs. 2 and 3, carry the teeth, chisel bits or cutters 'which operate ata lower depth, These are centrally disposed with respect to the kerf andare comparatively narrow so as to form a lowermost center slot asindicated at 26 in Fig. 6.'

On certain others of the central links, namely the links 3-0, see Figs.4 and 5 the chisel bits 35 operate at a relatively-higher level. TheseVcutters 35 are relatively wider'than the lower cutters 25 and also aresymmetrically arranged` with respect to the center line of the kerf.Thus they balance forces against their opposite side edges. the totalwidth of the kerf 35 and to form the bottom wall thereoffas at the levelindicated-by the .numeral 31 in Fig. 6. The bottom wall of the centerslot 26 at the level defined bythe lower chisel cuttertooth 25 isdesignated 21 in Fig. 6.

Further in accordance `with the invention the cutting depth foreachofthe verticallyspaced chisel teeth or cutters 25 Aand 35 is determinedby a guard preferablycarried by the same link and which rides on asurface formed by the cutter of the 4other level. As seen in Figs.-l, 2,3 and 6, the links 2l)v have-at a level above the chisel tooth 25anon-cutting guard 28 comprising a fiat plate .which` may be mountedl onthe link 20 in a similar'manner as the sharp edged cutters 35 on thelinks 3D and at a level corresponding tothe latter. Theseguards 28having a width not greater and preferably slightly less than the kerf 36are adapted to ride on the bottom- 31 of` the latter. They limit thedepth of the center slot 2B cut by the tooth -25 upon the same link 2U.

In a reciprocal and correlated fashion excessive penetration by thehigher-level teeth 35 of the links is guarded against by an underlyingnon-cutting guard 38 shown as a portion` of the rear leg 32-of theparticular link 30. This guard portion 38 by riding on the bottom 21 ofthe center slot 25 limits the depth of the bottom wall31'of the lkerf35.

Thus the vertically spaced teeth or `cutters25 and ofthe links 20 and 30are reciprocally guarded so that neither can penetrate more than alimited-distance beyond the other.' In this manner the work of cuttingand forming the kerf is divided between the two levels of teeth andneither one is freeto dig into thewood beyond the calculated extent.This depth of penetration is determined by theheight relationshipbetween each tooth 25 or 35 and its own guard 28 or 38 respectively, asmeasured with respect to the other positioned tooth and its guard. Theresultant chain as herein disclosed has in practice afforded a highlyeffective cutting action, requiring less power than the conventionalform. Some of the central links, herein the links 48, shown by wayof'example asV alternating between the `cutter links 28 and 30, have nocutters but being formed of similar blanks as the others-do 'have rearpendent legs 42. These may serve as clearers or rakers and may aord asupplemental guarding action in which connection they may also besupplied with guards or gauges similar tothe members 28 of the cutterlinks 20 if so desired.

The upper-level cutters 35 act to dene" Turning now to the furtherembodiment of.

series of links comprises right-hand cutter links 288, left-handcutterlinks 300 and intermediate non-cutting or clearer links 408, withpendent legs 220, 320 and 420 respectively. As in the previous examplethese may all have a common size and shape of blank one of which is seenseparately in Figfllvf The central-links 200,` 300, 400 as beforeare`pivotallyinterconnected by pairs of -connector 'links 500i-and5LB-some of which in this Ainstance additionally affordthe guarding andguiding function -to be-described.

In this Fig. 'l embodiment the'mutually cooperative cutter elements orteeth? proper have the form of -small plows, respectively disposed onthe several linksin a-siderelationship instead of vthe verticalrelationship-of thepreced. ing example. While they may be-formeddntegrally with the respective 'carrier links, preferably theyarefashioned separately as tool bits, of a special high-grade steel aspreviously mentioned, inserted and secured on'the rearlegs of the blanksas already explained;

Figs. l0 and ll show separately one of the cutter-links, namely-aright-hand link20ll.`Y For the purposes of description the terms rightand left are applied to the-chain' saw andl the kerf las viewed 'from aposition toward which the active run of the chain is travelling In Fig.`'1 the travel obviously is from right to left; and thepositionaldesignations are applied as if looking endwise onto Fig. 'I from theleft portion of the sheet.` Thus in Fig.A 10 the plow or 'cutter tooth250 is projected to the-right of the link 200. In Fig. ll which is aright side elevational view` of a cutter link20ll ithe tool bit or plowtooth 250 will be understood as laterally projective Yout from the sheetand toward the viewer. The same applies also 'tothe cutter rlink 208seen atthe'left portion of'Fig; 7, the latter to be compared also withthe bottom plan of Fig. 8 and the cross-sectional and end elevationalview of Fig. 9.

It 'will' be noted'that the sharpened lower cut'- ting edge of'the'plowor'tooth' 258'has a slight inclination in two'directions; thatis, upwardly 'fromright to vleft'as'seeninFigs'Q and V`10`.andalsoforwardlyirom the 'center' line of the kerf toward the side at whichthe tooth projects, noting particularly'ig; 8 in the latter connection.'The plow 'teeth or cutters '350 for th'e'left-'hand links 380er@simi'l'arlybutoppositely constructed and' arranged, laterally'ofthe' sawchain, as cleary seen" at the .lower `right central portion of Fig.

ByV reason of the plow-shape of the teeth' 250 and 358 the ribbon-likechips are turned away .from the'respective" teeth toward and-.into the`space at'the other side of the vkerf where they ,are taken up andcarriedvalong For this purpose intermediate central links 4D8as intheprevious 'instance have'the rear legs 420"of vtheir blanks constitutedas blunt or non-cutting clearers or rakers 440.

vIn Vthis Fig, 7 embodiment the horizontally offset cutterteeth 250 and350 of the cutting links 200 and 300 are reciprocally guarded as todepth of penetration, by rightand left-hand means which also aid asrakers or clearers. Such means may be formed on the central links butpreferablyr and as here shown is carried by certain of the connectorlinks 510, one of which is seen separately in Fig. 12. The meansVreferred to comprises generally rectangular feet II and 5I2 pendentfrom the selected side connecting links 5IIl and having straightelongated bottom edges 5I3, 5M. As illustrated these depth guards areprovided on one connector link 5H] of alternate pairs, and alternatelyat the left and at the right. The other connective link pairs 500 maybesimilarly equipped or left plain as shown. I

These rakers and depth gauges 5I I and 5I2 are adapted tov ride on theuncut lateral portion of the kerf on the side opposite to the particularcutting tooth 250 or 35D which they guard, herein that next following.Thus, starting at the left in Fig. 7, a left-hand raker-guard 5II guideson the track just previously made by a left-hand tooth 35B (passedbeyond Fig. '7) and thereby limits the depth of cut-to be made by thefollowing right-hand tooth 2'50. In similar reciprocal fashion theleft-hand cutting teeth 35, noting the central portion of Fig. 7, havethe cutting depth gauged by the precedent right-hand guard 5I2travelling on the right-hand track just cut by the right-hand tooth 250immediately ahead of it.

The eiectiveness of the depth guarding action will be apparent from thefollowing consideration. No single cutter or tooth 250 or 350 can digbelow the active cutting level as shown in Fig. 7 unless permittedtortilt in a counterclockwise direction about the rear rivet or pivotalconnective point 25| or 35I of the respective carrier link 200 or 30|).Such tilting mustinvolve a down movement of the leading portion of thesame carrier link 230 or 30G, in the region of the fore pivotalconnective point 252 or 352. Such down movement in turn is prevented bythe contact of the guard surface 5I3 or 5I4 of the corresponding guard5II or 5I2 upon the uncut wood at the opposite half of the kerf to thatof the particular guarded tooth 2'50 or 350. In other words, theleft-hand guards 5I I coacting with the left portion of the kerf aredirectly and -positively associated with the fore portions of thecarrier links 26D having the right-hand cutting teeth 25) and limit thecut depth thereof. Similarly,lthe right-hand guards 5I2 engagingdownwardly upon the right portion of the kerf are effectively carried atthe fore portion of the carrier links 300 having the left-hand teeth 350and accordingly control the cut depth of the latter. Thus in the Fig. 7embodiment a reciprocal and correlated guarding action is had for thehorizontally differentiated teeth 250 and 350 in a substantially similarmanner as for the vertically spaced cutting teeth 25 and 35 of theprevious embodiment. In both instances the cutters of one positionaltype are depth-guarded by a guard directly associated with the same linkas the particular cutter but which rides upon the horizontal surface ofthe kerf formed by a cutter of the other or another positional type,thereby aiording a reciprocal correlation for the cutting depth asbetween the dilferent positional types of cutters. It will be observedwith reference to both illustrative embodiments thatin'fthe saw. chainof the invention the work of cuttingthev kerfis divided between .twoseriesof teeth,-.the=y two series being in vertical. relationship .infonei instance and having a horizontal relationship in the otherexample. Each series of teeth is recipi-f. rocally guarded so that thoseof neither series cani penetrate more than a limited distancelbeyondthose ofV the other series. At the same time sub-# stantially completeVlateral balance is accorded, with a minimum tendencyv of objectionabledrag' or deviation at the sides ofthe kerf, the cutting-` elements beingin each case symmetrically arranged with respect tothe center line ofthe kerf.'y By reason of this lateral symmetry there is balancing offorces against the opposite side portions ofthe chain.

A further important aspect of the inventionconjoint raker-guard elementsare adapted `to receive automatic grinding while the sawfis. inoperation in the normal manner, such grindingv herein being effectedforv example atrtheflocae: tion where the chain bends around thearcuate! guide means or idler pulley at the outer ends of the supportingframe or blade of the chain-saw. In Figs. 13 to 15 a grinder means andthe `manner vof cooperation with the saw chain rare' illustrated inconnection Iwith the horizontally spaced tooth construction such as thatof Figs.y 7to .12.

Referring now more particularly to Figs 13 and 14, the arcuate guidemeans for Athe chain shown by way of example as an idler pulley. islindicated at 60, it being understood asl running upon a'pulley shaft 5Icarried on the saw v'frame I5. The frame is longitudinally extendedintegrally or by means of a bracket 62.receiving support from the pulleyshaft and adapted to mount a rotary abrasive element, disc or grinder1U. As illustrated the grinder 'I0 has its shaft 'IIeccentricallyjournalled in a circular bearer 12 rotatably supported onthe bracket 62. Means is provided for rotatively adjusting the bearerl2, the latter as shown being formed with .cir-v cumferential teethv asat 13 engaged by a Wormvv 'I4 rotatable by knob 15. By

toregulate.. the depth of grind.l 'I'he grinder 10 may be driven througha exible shaft 16 driven from the saw power plant, motor or anyconvenient driven part of the saw assembly. The drive shaft 16 desirablyhas a detachable coupling 'with the grinder shaft 'II as at 11. Ifdesired an auxiliary pulleyV 18 may be providedfor independent operationof the grinder. ff

In Fig. 14, looking at the opposite sideofthe saw to Athat viewed inFig. 7, the-idler pulley 60 turns counterclockwise, and the lower runvofthe chain moves from left to right toward active cutting position withreference to the work. A lefthand cutter link 300 (using the same handdesignation as for Fig. 7) is at the grinding location.

at the region where 1n passing around link 300 has the relief anglethereof presented in correct grinding relation to the grinder 10, suchthat the latter tends to generate a circle of appropriate radius at thetooth surface. It

also. will be observed :that the guard surface 5M' Vbyp-the grinder 10.During operation the latter is. axially nxed and the location and pathof grinding action is as described whether the grinder 10 is itselfdriven at the desired speed as throughthe means illustrated by way ofexample in Fig. 13, or is left at rest while the chain saw runs. `pastit in grinding relation.

It is, apparent from thedescription in connectionwith the drawings thatthis commony and uniform grindingy action with respect'both .to thecutter teeth and to the corresponding guard surfacesis had by reason oftheir mutual construction and arrangement substantially as shownanddescribed, and particularly the relation. of theV pivot points 35|and 352 with respect to the said surfaces to be ground and to thebearing surfaces 501m and 5la of the connector links 500 v.and 510.These .latter engage the track osthe frame I5 and of the pulley E9 andaccordingly determine the radial distance of the tooth and .guardsurfaces concerned from the pulleyv axissBI.

In Fig. 15 a typical cutter tooth 356 and guard SI2 therefor asconsidered in Figs. 13 and 14 are shown on alarger scale in the workingposition, as when extended rectilineally between the idler or. arcuateguide 60 and the driving sprocket at the remote end of the frame I5. Asthus generally horizontally travelling along the kerf in cuttingwood,the guard 512 and the tooth 350 of the cutter link 300 respectivelyhave the rear- Ward relief, and the difference in height indicated bythebroken lines in Fig. 15, appropriate for the mutual depth-g-uarding andcutting functions. The depth or height difference indicated representsthe depth of freshcutto be made in the course of passage of theparticular cutter along thekerf. As explained in connection with Figs. 7to 12, each guard 5| I, 512 rides upon the i wood at the opposite halfof the kerf from that of the corresponding cutter 250, 350, therebycorrelatingthe cuttingaction of the horizontally .spaced series ofcutters.

Itis important to note here that as the cutter teeth gradually wear downin use the provisions for automatic `grinding asillustrated anddescribed in connection with Figs. 13 to 15 are such that the samemutual depth relationship is maintained as between the cutters and thecorresponding guards. The grinder 10 may be adjusted from time to timeby manipulation of the knob 15 to accommodate it to the extent of wearof the chain parts in actual operation. So far as I am aware the presentinvention for'the firsttime adapts a chain for accurate grinding whilerunning in anormal manner and makes provision for accomplishing thatresult.

It will be understood that while in the foregoing description `withrespect to Figs. 14 and 415 a left-hand cutter and tooth 30D, 350 hasbeen referred together with the corresponding guard 5I2 the samegrinding relation prevails also as to the cutter series 250 of oppositehandsfand to the guards 5H therefor.

My invention either as to means or method is not limited Ato theexemplary embodiments or steps herein illustrated or. described, and Isetforth its scope in my following claims:

I claim:

1. In a chain saw, an endless series of central links having pendentlegs, connector links pivotally connecting the central links, the legsof some of the central links carrying single chisellike bits providingcutter teeth formed -to cut with a paring action along a substantiallyYhori- Zontal surface, the legs of the other central links eachconstituted as a raker, said toothed links alternating with said rakerlinks in the central series, the cutter teeth of alternate toothed linksbeing positionally diflerentiated in the vertical and in the horizontaldirection transverse of the kerf so as to out diierent bottom portionsthereof, and a depth guard for each cutter-toothed link, such guard forthe given tooth being directly associated therewith and being shaped,dimensioned and arranged as to both the vertical and horizontaldirections so that such guard rides solely on that horizontal surfaceformed in the kerf by the precedent positionally differentiated cuttertooth.

2. A chain saw according to claim 1 in which the positionally differingcutter teeth are mutually onset vertically of the kerf and alternatelyare relatively wide and relatively narrow.

3. A chain saw according to claim 2 in which the depth guards forrunning on surfaces formed by the lower cutter teeth are carried on thesame links with the higher cutter teeth, and vice versa, in thereciprocal and mutually coactive relation.

HENRY E. WARREN.

References Cited in the le of this patent UNITED STATES PATENTS

